Count Arnold IV (II) von Kleve, also known as Graf von Kleve, was a noble figure born circa 1160 in Kleve, located in Rheinland, Prussia (modern-day Germany). He passed away around 1201, with his death occurring in Heinsberg, in the present-day North Rhine-Westphalia.
Immediate Family:

   Father: Dietrich IV, Count of Cleves

       Dietrich IV was an important noble figure, and as Arnold's father, he helped establish the lineage and influence of the von Kleve family.

Mother: Adelheid von Sulzbach

       Adelheid's noble heritage added to the prestige of the family, as Sulzbach was a notable family in the Holy Roman Empire during the 12th and 13th centuries.

Wife: Adelheid von Kleve

       Arnold's marriage to Adelheid von Kleve continued the family legacy within the von Kleve line. It’s not uncommon during this period for noble families to intermarry to consolidate power and maintain influence within their regions.

Children:

Arnold IV and Adelheid had several children who continued the von Kleve family's legacy:

   Dietrich I von Kleve, Graf von Heinsberg und Valkenburg

       Dietrich I was an important figure in his own right, as he held lands in Heinsberg and Valkenburg, suggesting that the von Kleve family expanded their influence through strategic land holdings and marriages.

   Beatrix von Randerath

   Agnes von Kleve

   Arnold V von Kleve

       Arnold V would have carried on the von Kleve name and title, continuing the family's presence in noble and political affairs.

Siblings:

Arnold IV had several siblings, which further connects the von Kleve family to other noble houses in the region:

   Margareta von Thüringen

       Margareta was likely married into another noble family, further connecting the von Kleve family to broader regional alliances.

   Dietrich von Kleve, III./V.

       Dietrich, as a sibling, would have been a significant figure, potentially serving in military or political roles alongside Arnold IV.

   Gerhard von Kleve

   Adelheid von Kleve, Gravin van Holland

       Adelheid's marriage into the Holland family is particularly noteworthy. Gravin van Holland (Countess of Holland) would have given the von Kleve family strong connections with the ruling class in the County of Holland, an important and powerful region in the Low Countries.

Historical Context:

Arnold IV was part of the von Kleve family, which held important territories in Westphalia and was connected to various political and noble alliances in the Holy Roman Empire. His death around 1201 places him in the late 12th to early 13th century, a period of significant political and territorial change in Europe, with the consolidation of power by various noble houses.

   The Holy Roman Empire: The von Kleve family was a part of the complex structure of the Holy Roman Empire, with its many competing principalities, territories, and kingdoms. The family’s strategic marriages and alliances were key to maintaining influence in this volatile political landscape.

   The Crusades: The 12th and 13th centuries saw the ongoing Crusades, which could have had an impact on the power dynamics of noble families like the von Kleve family. They might have been involved in some way, either through direct participation in the crusades or through the political ramifications of these events.

   The Rise of the Duchy of Kleve: Over the following centuries, the Duchy of Kleve would rise to significant prominence, especially during the reign of the von Kleve family in the 16th century. Although Arnold IV lived before this height of the family’s power, his descendants, including his children, would contribute to the eventual formation of a Duchy.

Conclusion:

Count Arnold IV (II) von Kleve was a significant noble figure in the late 12th century, connected to influential families through both his immediate and extended family ties. His marriage to Adelheid von Kleve and his children, including Dietrich I von Kleve and Arnold V von Kleve, continued the von Kleve family's political and territorial legacy. His family's alliances, such as Adelheid von Kleve's marriage into the Holland family, strengthened the von Kleve family's influence, and it would continue to grow in power after his death.